The invention relates to a spectral microscope with a photometer.
Microscopes with a photometer and a monochromator (microspectrophotometer) serve to determine the spectral distribution of radiation. The object to be examined is here illuminated by a light source and the radiation altered by the object is measured. A microspectrophotometer of this type is known from German Offenlegungsschrift 2,542,731. This publication describes a microscope with separate retrofittable auxiliary devices which can be optionally attached to the microscope. One of these auxiliary devices has a grating monochromator with an entrance slit, a concave mirror and also an optical grating. The photometer is arranged in an auxiliary device and is connected to the monochromator via a further retrofittable attachment. By exchanging a plane mirror for the grating, this microscope can be used both as a spectrophotometer and as a pure photometer. The device described here is very expensive due to the high outlay for adjustment between the retrofittable constructional units and functional units. Moreover, with a device of this type it is not possible to measure a preselectable object point both densitometrically and spectrophotometrically at the same time.
A measuring microscope which has an attachable constructional unit for densitometric and spectrophotometric measurement of the light coming from the object is known from German Offenlegungsschrift 3,432,252. For this, an optical slit is provided in the constructional unit in an intermediate image plane of the object. Following this is a partially transmitting mirror for producing two separate beams. One of these beams contains a photometer with photomultiplier, while the concave reflection grating and also a diode array for spectrophotometric measurement are arranged in the other beam. Besides the expensive construction, with this measuring microscope it is only possible to measure in the optical axis, so that the measuring surface of the object can only occur by a displacement of the object with a scanning stage. In addition, it is not possible here to make the slit image and the associated spectral lines visible in the eyepiece.